Anew generation of high-capacity, long-life lithium-ion battery anode "red phosphorus-graphene"nanocomposite material

HC Chemical Network News: Lithium-ion batteries as high-energy-density energy storage devices are widely used in portable electronic products such as mobile phones and notebook computers.  And nowadays eye-catching electric vehicles use lithium-ion batteries as their main source of power.  This puts forward more stringent requirements on the performance of lithium-ion batteries: higher energy density, longer service life, and wider operating temperature window.  However, graphite, which is currently commercialized as a negative electrode material for lithium-ion I batteries, is difficult to meet these requirements due to its low theoretical capacity (-370mAh/g).  Therefore, scientific researchers in the corresponding fields around the world are looking for the next generation of lithium-ion battery anode materials.

In response to this problem, a scientific research team led by Professor Wang Donghai from The Pennsylvania State University (ThePennsylvania State University), led by Yu Zhaoxin and Song Jiang, invented a new type of lithium-ion battery anode material:'red phosphorus-graphene' nanocomposite material. This kind of material is prepared by ball milling of red phosphorus and graphite. Red phosphorus has high chemical stability, is cheap and easy to obtain, and is environmentally friendly. Its theoretical capacity as a negative electrode material for lithium-ion batteries can reach 2600mAh/g, which is 7 times that of commercial graphite electrodes. Graphite/graphene is introduced into the system due to its extremely high electronic conductivity to improve the overall electronic conductivity of the nanocomposite, In the process of high-speed ball milling, micron-sized red phosphorus particles are broken down to nano-sized. Graphite is exfoliated into graphene with a large specific surface area during the ball milling process. After a long time of mechanical force, the graphene overlaps each other to form a tightly coupled three-dimensional conductive network, and the nano-scale red phosphorus particles are uniformly dispersed in the network. Infrared spectroscopy (InfraredSpectroscopy) tests show that red phosphorus and graphene are combined in the form ofphosphorus-oxygen-carbon (P-O-C)' chemical bonds, which in turn provides a guarantee for the material's outstanding battery performance. At room temperature, the discharge capacity of the nanocomposite material can reach 1400mAh/g, which is 4 times the current commercial lithium-ion battery anode material-graphite. After a 300-week cycle, the discharge capacity can still be maintained above 60%. The high temperature environment (60°C) is still a big challenge for the current commercial lithium-ion batteries. With this material, the discharge capacity can be further increased to 1650mAh/g at 60°c. After 200 cycles of cycles, the discharge capacity retention rate can be above 70%.

High-capacity, long-life, low-cost raw materials, and synthetic methods suitable for industrial production, these factors have promoted the new "red phosphorus-graphene" nanocomposite material to become the choice of next-generation lithium-ion battery anode materials.